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Heracleum maximum (syn. H. lanatum)

Common cow parsnip

Genus: Heracleum, Named for Hercules, who was supposed to have used it first for medicine. Also thought to be named after Hercules because he was considered a mortal of great size and strength much like the plant
Species: lanatum- covered with long, wooly hair

Family Characteristics: Apiaceae (Carrot of Parsley family). Stems often hollow between nodes, leaves are generally compound with strongly sheathing leaf bases, flowers are in umbels, sometimes compound.

Characteristics of this plant:
Growth: Cow parsnip is tall (stands 1-3 m)
Roots: Stout taproot, fleshy fibrous roots
Stems: Stem is erect, branched, hairy and hollow. Usually 1-2.5m tall and 2cm in diameter. Leaf is ternate (having 3 leaflets); each leaflet is lobed, deeply toothed, and finely serrate.
Inflorescence: White flowers are large compound umbels 15-30cm across. Some flowers only produce stamens, while other produce bisexual flowers that produce seed. Primary umbels produce 80% of the seed. Blooms March to May
Fruits: The fruit is oblong, 8-12mm long with very fine hair. The fruit is marked on the faces by narrow ribs and dark lines. Some think the fruit has a disagreeable smell.

Restoration: Cow parsnip is moderately good for soil stabilization and erosion control.

Habitat: Cow parsnip grows in a wide variety of forested habitat types, grasslands, shrublands, meadows, alpine, and riparian zones. Around the Marin Headlands it occupies well-shaded, moist places. Grows in seral to climax communities. Not common in disturbed areas, cow parsnip is sensitive to soil compaction and severe soil disturbances.

Ethno botanical information: The Cree gathered young Cow Parsnip stalks and roasted them on hot coals, later eating the pith. Young roots were also cooked as a vegetable, like parsnip. Medicinally, pastes of dried grated roots were applied to swollen legs to relive swelling and were used on aching limbs and heads to relive pain. Young leaf stalks and stems, before flowering, were eaten like stewed celery

Heracleum maximum (syn. H. lanatum) Characteristics


  • Evergreen
  • California native
  • Portola Valley Ranch approved

Flower color

  • White / Cream / Ivory

Foliage color

  • Green / Blue-green

Growth habit (plant shape)

  • Upright


  • Morning sun
  • Light or dappled shade
  • Sunny all day - Coast

Season of interest (flowering)

  • Spring

Season of interest (foliage)

  • Year round

Your soil type

  • Sandy loam
  • Clay-loam
  • Loam
  • Clay

Water requirements

  • None

Critter resistance

  • Deer resistant
  • Rabbit resistant

Wildlife appeal

  • Attracts butterflies
  • Attracts beneficial insects
  • Attracts birds
  • Attracts bees

Suggested uses

  • Water feature


  • California

Plants that work well with Heracleum maximum (syn. H. lanatum)

California fescue California fescue (Festuca californica)
California goldenrod California goldenrod (Solidago velutina ssp. californica)